Grinding machine with workpiece locator assembly

ABSTRACT

An improved workpiece locator or sensor assembly is utilized in association with a grinding machine to detect when either a left or right reference surface on a workpiece has been moved to a predetermined position in a work area. The workpiece locator assembly includes a probe member which is moved by a double acting motor into engagement with either a right or left reference surface. The probe member is connected with the motor by a yieldable connection which includes two springs of the same free lengths. The workpiece locator assembly can be utilized to locate either a right or left reference surface. In addition, a selector valve can be associated with the motor to effect operation of the locator assembly to first locate a right reference surface on one workpiece and to subsequently locate a left reference surface on a second workpiece without disassembling the locator assembly.

lJnited States Patent [191 Fournier Dec. 24, 1974 GRINDING MACHINE WITH WORKPIECE LOCATOR ASSEMBLY [75] Inventor: Roger H. Fournier, Millbury, Mass.

[73] Assignee: The Warner & Swasey Company, Cleveland, Ohio 22 Filed: Mar. 28, 1973 211 Appl. No.: 345,693

[52] US. Cl. 51/165 R, 51/105 SP, 51/l65.92 [51] Int. Cl B24b 49/00 [58] Field of Search 51/105 SP, 105 R, 165 R,

Primary Examiner-Harold D. Whitehead [57] ABSTRACT An improved workpiece locator or sensor assembly is utilized in association with a grinding machine to detect when either a left or right reference surface on a workpiece has been moved to a predetermined position in a work area. The workpiece locator assembly includes a probe member which is moved by a double acting motor into engagement with either a right or left reference surface. The probe member is connected with the motor by a yieldable connection which includes two springs of the same free lengths. The workpiece locator assembly can be utilized to lo cate either a right or left reference surface. In addition, a selector valve can be associated with the motor to effect operation of the locator assembly to first 10- cate a right reference surface on one workpiece and to subsequently locate a left reference surface on a second workpiece without disassembling the locator assembly.

18 Claims, 12 Drawing Figures GRINDING MACHINE WITH WORKPIECE LOCATOR ASSEMBLY BACKGROUND OF THE INVENTION This invention relates generally to a workpiece locator assembly and more specifically to the workpiece locator assembly which can be utilized to detect when either a right or a left reference surface on a workpiece is in a desired position.

There are many known workpiece locator assemblies which are utilized to determine when a reference surface is in a predetermined position relative to a grinding wheel or a cutting tool. Generally speaking, these workpiece locator assemblies are constructed so that they can be utilized to detect the position of either a right reference surface or a left reference surface relative to the work area. These known workpiece locator assemblies cannot be utilized, without extensive modifications or changes, to sequentially locate a right reference surface relative to the work area and then to locate a left reference surface relative to the work area. Thus, these known workpiece locator assemblies are utilized to locate reference surfaces which face the same direction relative to the work area, that is for the purpose of locating only right reference surfaces or only left reference surfaces relative to the work area. One of those knownn workpiece locator assemblies is disclosed in U.S. Pat. No. 3,064,395.

Another known workpiece locator assembly is utilized to determine when two reference surfaces which face toward each other are in a desired position in a work area. This known locator assembly includes a rotatable cam which is disposed on the outer end of a probe member. This cam is rotated so that opposite side surfaces on the cam simultaneously engage the two reference surfaces. The construction of this known locator assembly is disclosed on US. Pat. No. 3,098,328.

SUMMARY OF THE PRESENT INVENTION A workpiece locator assembly constructed in accordance with the present invention can be utilized to de tect when a right or left reference surface is in a predetermined position in a work area. To facilitate sequential operation on workpieces having different shapes, the locator assembly can be utilized to locate a right reference surface on one workpiece relative to the work area and to subsequently locate a left reference surface without disassembling the locator assembly. The locator assembly includes a probe member having a first side surface for engaging a left reference surface on a workpiece during the locating of this workpiece in a predetermined position in a work area. The probe member also has a second side surface which engages a right reference surface on another workpiece as it is being positioned in the work area.

The probe member is connected with a double acting motor by a yieldable connection which enables the probe member to move relative to the motor. This yieldable connection includes a pair of springs of the same free length. The springs press the probe member against the workpiece so that the probe member will follow the workpiece as it moves to the predetermined position. Thus, if the locator assembly is to be utilized to detect when workpieces having a right reference surface are disposed in a predetermined position in a work area, one of the two springs presses one side of the probe member against the right reference surface. If

LII

the locator assembly is utilized to determine when a left reference surface is in a predetermined position in the work area, the other spring presses the opposite side of the probe member against the left reference surface.

To enable the locator assembly to be utilized to sequentially locate a right reference surface on a first workpiece relative to a work area and to thereafter locate a left reference surface on another workpiece relative to the work area, a selector valve is associated with the motor. Actuation of this selector valve to a first position enables the motor to pivot the probe member in a first direction from an inactive condition to an active condition when the probe member is to be utilized to locate the right reference surface. Similarly, actuation of the selector valve to a second position enables the motor to pivot the probe member in a second direction from an inactive condition to an active condition when the probe member is to be utilized to locate a left reference surface.

Accordingly, it is an object of the present invention to provide a new and improved workpiece locator as sembly which can be utilized to detect when either a right or a left reference surface on a workpiece is in a predetermined position in a work area.

Another object of this invention is to provide a new and improved workpiece locator assembly which can be utilized to detect when a right reference surface on a first workpiece is in a predetermined position in a work area and to subsequently detect when a left reference surface on a second workpiece is in a predetermined position relative in the work area.

Another object of the invention is to provide a new and improved workpiece locator assembly having a probe member which is connected with a motor by a yieldable connection which is formed by a pair of springs which are disposed on opposite sides of the probe member in a coaxial relationship with each other.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects and features of the present invention will become more apparent upon a consideration of the following description taken in connection with the accompanying drawings wherein:

FIG. 1 is a partially broken away illustration of a grinding machine having a workpiece locator assembly constructed in accordance with the present invention;

FIG. 2 is an enlarged elevational view, taken along the line 2-2 of FIG. 1, further illustrating the construction of the workpiece locator assembly;

FIG. 3 is a sectional view, taken generally on the line 33 of FIG. 2, illustrating the condition of a pair of springs in a yieldable connection which interconnects a probe member and double acting motor in the locator assembly as a right reference surface moves to a predetermined position in a work area;

FIG. 4 is a fragmentary sectional view, generally similar to FIG. 3, illustrating the condition of the pair of springs as a left reference surface moves to a predetermined position in the work area;

FIG. 5 is a schematic illustration of the locator assembly in an inactive condition with the springs in an initial condition in which they are compressed to the same length;

FIG. 6 is a schematic illustration of the locator assembly of FIG. 5 in an active condition in which the springs are in the condition shown in FIG. 3 and the locator assembly is effective to detect when a right reference surface is in a predetermined position;

FIG. 7 is a schematic illustration of the locator assembly in an inactive condition with the springs in the initial condition;

FIG. 8 is a schematic illustration of the locator assembly of FIG. 7 in an active condition in which the springs are in the condition shown in FIG. 4 and the locator assembly is effective to detect when a left reference surface is in a predetermined position;

FIG. 9 is a schematic illustration of a second embodiment of the locator assembly in an active condition in which it is effective to detect when a left reference surface on a workpiece is in a predetermined position;

FIG. 10 is a schematic illustration of the locator assembly of FIG. 9 being utilized to detect when a right reference surface on another workpiece is in a predetermined position;

FIG. 11 is a schematic illustration of hydraulic control circuitry which is utilized in association with the grinding machine of FIG. 1; and,

FIG. 12 is a schematic illustration of electrical control circuitry of FIG. 11.

DESCRIPTION OF SPECIFIC PREFERRED EMBODIMENTS A workpiece locator or sensor assembly is illustrated in association with a known grinding machine 22 having a headstock 24 and a tailstock 26 which cooperate to support and rotate a workpiece 28 in a work area 30. During operation of the grinding machine 22, a grinding wheel 34 is rotated by a motor 36 through a drive train 38 to cut material from the workpiece 28 as it is rotated about its central axis under the influence of forces transmitted to a headstock spindle 40 by a multi-sheave pulley arrangement 42. A tailstock spintile 46 is pressed against the workpiece 28 under the influence of a biasing spring 48.

To locate a shoulder or reference surface 52 in a desired position, the headstock 24 and tailstock 26 are first adjusted to locate the workpiece 28 in a position in which the reference surface is to the right of the desired position. A drive arrangement 56 is then activated to move the headstock spindle 40 toward the left (as viewed in FIG. I). The spring biased spindle 46 of the tailstock 26 presses the workpiece 28 toward the left as the headstock spindle 40 is moved leftwardly.

When the workpiece 28 has been moved axially toward the left through a distance sufficient to move the reference surface 52 into the desired position relative to the work area 30, a probe assembly 60 is pivoted in a counter clockwise direction (as viewed in FIG. 1) to actuate a detector switch 64. Actuation of the detector switch 64 interrupts operation of the drive arrangement 56 with the reference surface 52 in the desired position relative to the grinding wheel 34. The construction and general mode of operation of the grinding machine 22 is the same as is disclosed in U.S. Pat. No. 3,l7l,234 and to avoid prolixity of description, the disclosure in that patent is to be considered as being incorporated herein in its entirety by this reference thereto.

In accordance with the present invention, the workpiece Iocator assembly 20 can be utilized to detect when either the right reference surface 52 or a left reference surface 70, is in a predetermined position in the work area 30. Accordingly, the probe assembly 60 includes a probe member 74 (see FIGS. 2 and 3) having a first side or locating surface 76 (FIG. 3) which engages the right shoulder or reference surface 52 and a second side or locating surface 78 which engages the left shoulder or reference surface 70. Regardless of which locating surface on the probe member is being utilized, an actuator arm 82 and support shaft 84 (FIGS. 2 and 3) are rotated about a central axis 86 to actuate the detector switch 64 (FIG. 1) when a reference surface 52 or engaged by a side or locating surface 76 or 78 on the probe member 74 is moved to the predetermined position in the work area 30. To enable the locator assembly 20 to be utilized with different lengths of workpieces, the locator assembly includes a carriage 88 (FIG. 2) which is slidably mounted on a bedway 90. A suitable clamping arrangement 92 is provided to lock the carriage 88 in a position such that the actuator arm 82 will actuate the limit switch 64 when a reference surface engaged by the probe member 74 is in a desired position in the work area 30.

A double acting fluid motor 98 is utilized to pivot the probe member 74 about the axis 86 from an inactive position in which the side or locating surfaces 76 and 78 are spaced apart from the reference surfaces 52 and 70 (FIGS. 5 and 7) and an active position in which one of the locating surfaces 76 or 78 is engaged by one of the reference surfaces 52 or 70 (FIGS. 6 and 8). Thus, when the locator assembly 20 is to be utilized to detect when a right shoulder or reference surface 52 is in a predetermined position in the work area 30, the double acting motor 98 pivots the probe member 74 in a clockwise direction from the inactive condition of FIG. 5 to an active condition. When the probe member 74 is in the active condition, leftward movement of the workpiece brings the reference surface 52 into engagement with the side surface 76 on the probe member 74. Continued leftward movement of the workpiece 28 under the influence of the head and tailstocks 24 and 26 causes the probe member 74 to be pivoted in a counterclockwise direction (as viewed in FIGS. 5 and 6) to actuate the limit switch 64 when the reference surface 52 has been moved to the desired position in the work area 30 (as illustrated in FIG. 6).

Similarly, when the workpiece locator assembly 20 is to be utilized to detect when the left reference surface or shoulder 70 is in a predetermined position in the work area 30, the motor 98 is activated to move the probe member 74 from an inactive condition (FIG. 7) in which the side or locating surface 78 is spaced from the reference surface 70 to an active condition in which the side locating surface 78 engages the reference surface 70 (FIG. 8). Thus, the motor 98 is actuated to pivot the probe member 74 in a counterclockwise direction about the axis 86 toward the active condition of FIG. 8. As the probe member 74 is pivoted toward the active condition, the side surface 78 on the probe member 74 moves into abutting engagement with the left reference surface 70.

After the probe member 74 has engaged the left reference surface 70, the workpiece 28 is then moved towards the left (as viewed in FIG. 1) under the influence of the head and tailstocks 24 and 26. When the reference surface 70 is located in the desired position in the work area 30, the actuator arm 82 actuates the detector switch 64 (FIG. 8) to interrupt the leftward axial movement of the workpiece 28 under the influence of the head and tailstocks 24 and 26.

The probe member 74 and actuator arm 82 are in the same orientation when the detector switch 64 is actuated to indicate that a right reference surface 52 is in a predetermined position (see FIG. 6) as when the detector switch is actuated to indicate that a left refer ence surface 70 is in its predetermined position (see FIG. 8). However, the probe member 74 is pivoted in one direction from an inactive condition to engage the right reference surface 52 and is pivoted in the opposite direction from an inactive condition to engage the left reference surface 70. This requires that the motor 98 be operated in one direction to move the probe member 74 into engagement with a right reference surface 52 and in the opposite direction to move the probe member into engagement With a left reference surface 70.

To enable the motor 98 to be utilized to pivot the probe member in opposite directions from inactive conditons to active conditions, the probe assembly 60 is connected with the double acting motor by a yield able connection 106. The yieldable connection 106 (FIG. 3) includes two identical springs 110 and 112 which have the same free length and are disposed in a coaxial relationship with each other. The springs 110 and 112 are mounted on a piston rod 116 with washers 117 and are compressed to about three-quarters of their free length when the springs are in the initial condition of FIGS. 5 and 7. The piston rod 116 is connected with a piston 118 in a cylinder 120 of the double acting motor 98.

Since the springs 110 and 112 have the same free length and spring rate, they are both compressed to the same length between washers 117 when the probe member 74 is in the inactive condition of FIG. 7. In the inactive condition of FIG. 5, the spring 110 is compressed somewhat due to engagement of the probe member 74 with switch 64. Upon operation of the motor 98 to move the probe member 74 from the inactive conditon to the active condition of either FIG. 6 or 8, the probe member 74 moves into engagement with the reference surface 52 or 70 and continued operation of the motor 98 compresses one of the springs 110 or 112 and at least parially relaxes the other spring.

Thus, when the motor 98 is operated from the condition shown in FIG. 5 to the condition shown in FIG. 6, the probe member 74 is pivoted from the inactive condition to the active condition. During this pivoting movement of the probe member, the side surface 76 on the probe member moves in abutting engagement with the reference surface 52. Continued operation of the motor 98 results in the spring 112 being compressed while the spring 110 is partially relaxed. At this time, the right reference surface 52 is to the right of the position shown in FIG. 6 and the spring 112 presses the side surface 76 firmly against the reference surface 52.

As the workpiece 28 is moved toward the left from the position shown in FIG. 5 to the position shown in FIG. 6 under the influence of the head and tailstocks 24 and 26, the probe member 74 is pivoted in a counterclockwise direction about the axis 86 to further compress the spring 112. When the reference surface 52 reaches the position shown in FIG. 6, the probe member 74 will have been pivoted through a sufficient distance to actuate the detector switch 64 to interrupt operation of the head and tailstocks 24 and 26. At this time the springs 110 and 112 are in the condition shown in FIG. 3 with the spring 1 10 at least partially relaxed and the spring 112 almost fully compressed.

Similarly, when the locator assembly 20 is to be utilized to detect when a left reference surface is in a predetermined position relative to the work area, the motor 98 is operated from the condition shown in FIG. 7 to the condition shown in FIG. 8 to swing the probe member in a counterclockwise direction from the inactive position in FIG. 7. When the probe member 74 is in the inactive position of FIG. 7, the springs I10 and 112 have the same length. However, as the probe member 74 pivots in a counterclockwise direction, the side surface 78 moves into abutting engagement with the reference surface 70. Continued operation of the motor 98 moves the piston rod 116 relative to the 'probe member 74 to compress the spring and partially relax the spring 112. The compressed spring 110 holds the side surface 78 of the probe member 74 firmly against the reference surface 70.

As the workpiece 28 is moved toward the left (as shown in FIGS. 7 and 8), under the influence of the head and tailstocks 24 and 26, the spring 110 pivots the probe member 74 in a counterclockwise direction. As the reference surface 78 reaches the predetermined position in the work area 30, the probe member 74 moves into the position shown in FIG. 8 and the detector switch 64 is actuatedto interrupt movement of the workpiece 28. It should be noted that at this time the springs 110 and 112 will be in the condition shown in FIG. 4.

When the workpiece locator assembly 20 is to be utilized to detect the right reference surface 52 is in a predetermined position relative to the work area 30, the main control valve 126 is connected with the cylinder of the motor 98 by conduits 128 and 130 in the manner illustrated in FIG. 5. When the main control valve 126 is in its normal or unactuated condition, fluid under pressure is ported to the conduit 128 and the rod end of the cylinder 120 from a pump 131 and the head end of the cylinder 120 is connected with drain through the conduit 130. Since the springs 110 and 112 are arranged as shown in FIG. 5, the spring 110 is compressed somewhat since the actuator arm 82 will engage an input member 133 to a pressure gauge 136 (FIG. 5).

Actuation of the main control valve 126 (FIG. 6) results in fluid under pressure being ported to the conduit 130 which is connected with the head end of the cylinder 120. This results in movement of the piston 118 to swing the probe member 74 in a clockwise direction from the inactive condition of FIG. 5 to the active condition.

When the probe member 74 is initially moved to the active position, the right reference surface 52 is disposed to the right of the position shown in FIG. 6 and, the actuator arm 82 is ineffective to actuate the switch 64. As the workpiece 28 is moved toward the left (as viewed in FIG. 5) under the influence of the head and tailstocks 24 and 26, the right reference surface 52 pivots the probe member 74 in a counter clockwise direction about the axis 86. This pivotal movement of the probe member 74 causes the actuator arm 82 to further compress the spring 112 and actuate the detector switch 64 when the right reference surface 52 is in a predetermined position relative to the work area 30 (FIG. 6). It should be noted that the actuator arm 82 and probe member 74 are movable relative to the piston rod 116 against the influence of the springs 110 and 112. The springs 110 and .112 will be in the condition shown in FIG. 3 when the reference surface 52 reaches the predetermined position.

When the workpiece locator assembly 20 is to be used to detect when a left reference surface or shoulder 70 on a workpiece 28 is in a predetermined position relative to the work area 30, the conduit 130 is connected with the rod end of the cylinder 120 and the conduit 128 is connected with the head end of the cylinder 120 in the manner shown in FIG. 7. Therefore, when the main control valve 126 is in the normal or unactuated position, fluid under pressure is conducted to the head end of the cylinder 120 to extend the piston rod 116 in the manner shown in FIG. 7. The springs 110 and 112 hold the probe member 74 in the inactive condition in FIG. 7 and the piston 118 at the left end of the cylinder 120.

Upon actuation of the main control valve 126, high pressure fluid is ported to the conduit 130 and the rod end of the cylinder 120. This results in rightward movement of the piston 118 to pivot the probe member 74 in a counterclockwise direction. This moves the side or locating surface 78 on the probe member 74 into abutting engagement with the left reference surface 70. At this time the reference surface 70 will be to the right of the position shown in FIG. 8. Therefore, the piston rod 116 will continue to move relative to the probe member 74 and the spring 110 will be compressed.

As the workpiece 28 is moved toward the left from the position shown in FIG. 7 to the position shown in FIG. 8 under the influence of the head and tailstocks 24 and 26, the spring 110 urges the probe member 74 in a counterclockwise direction about the axis 86 to maintain the locating surface 78 in abutting engagement with the left reference surface 70. As the reference surface 70 reaches a predetermined position in the work area 30, the probe member 74 moves to the position shown in FIG. 8 under the influence of spring 110. The spring 110 is then effective to press the actuator arm 82 against the detector switch 64 and pressure gauge 136 to positively actuate the detector switch. Actuation of the detector switch 64 effects the operation of cylinder control circuitry to interrupt movement of the workpiece 28 by the head and tailstocks 24 and 26. It should be noted that the springs 110 and 112 are in the condition shown in FIG. 4 when the actuator arm 82 is effective to actuate the switch 64.

In the embodiment of the invention disclosed in FIGS. 5-8, the main control valve 126 is spring biased to the normal position illustrated of FIGS. 5 and 7 and is actuated from this normal position by an energization of a solenoid 134. Since the solenoid 134 is energized to effect operation of the probe assembly 60 from the inactive position of either FIG. 5 or FIG. 7 to the active position of either FIG. 6 or FIG. 8, the main control valve 126 can be utilized with the same machine control circuitry regardless of whether the probe assembly 60 is to be used to detect a right or left reference surface. However, it is necessary to reverse the connections of the conduits 128 and 130 with the fluid motor 98. Of course, if desired, the main valve 126 could be changed rather than changing the connections for the conduits 128 and 130.

It is contemplated that under certain circumstances the grinding machine 22 may be utilized to sequentially operate on workpieces having reference surfaces facing in opposite directions. Thus, the grinding machine 22 may be utilized to shape a workpiece having a right reference surface or shoulder 52 and then subsequently utilized to shape a workpiece having a left reference surface or shoulder 70. The conduits 128 and 130 could be changed from the condition shown in FIG. 5 to the condition shown in FIG. 6 when the machine is to be changed from operating on a workpiece having a right reference surface 52 to the workpiece having a left reference 70. However, changing the conduits 128 and 130 contributes to the down-time of the grinding machine 22.

Accordingly, a selector valve 138 is connected with the conduits 128 and 130 in the manner shown in FIGS. 9 and 10 to enable the probe assembly 60 to be quickly changed from a condition locating a left reference surface (FIG. 9) to a condition locating a right reference surface 52 (FIG. 10). The selector valve 138 is connected with the main control valve 126 by a conduit 128a and is connected with the head end of the cylinder by a conduit 12812. The selector valve 138 is also connected with the main control valve 126 by conduit a and is connected with the rod end of the cylinder 120 by a conduit 130b. Actuation of the selector valve 138 between the condition shown in FIG. 9 and the condition shown in FIG. 10 merely reverses the flow of fluid to the motor 98.

When the probe assembly 60 is to be utilized to locate a left reference surface 70, the selector valve 138 connects the conduit 128a with the conduit 128b and the conduit 130a with the conduit 13%. Acutation of the main control valve 126 from the position shown in FIG. 7 to the position shown in FIG. 9 effects operation of the motor 98. This operation of the motor 98 moves the probe member 74 from the inactive condition of FIG. 7 toward the active condition of FIG. 9. Of course, when the left reference surface 70 is moved to a predetermined position in the work area 30, the actuator arm 82 actuates the detector switch 64 in the manner previously explained in association with FIG. 8.

If the next succeeding workpiece 28 has a right reference surface 52, the selector valve 138 is operated to the condition shown in FIG. 10 to reverse the fluid connections between the main control valve 126 and motor 98. Thus, the selector valve connects the conduit 128a with the conduit l30b and the conduit 1300 with the conduit 128b. Actuation of the main control valve 126 from the initial position of FIG. 5 to the activated position of FIG. 10 effects operation of the motor 98. This operation of the motor 98 moves the probe member 74 from an inactive condition to the active condition of FIG. 10. As the right reference surface 52 is moved to the desired position relative to the work area 30 under the influence of the head and tailstocks 24 and 26, actuator arm 82 compresses the spring 112 and activates the detector switch 64 in a manner similar to that previously explained in association with FIG. 6.

A hydraulic control circuit for coordinating operation of the probe assembly 60 with operation of the head and tailstocks 24 and 26 is illustrated in FIG. 11

in association with the workpiece 28 having a left reference surface 70. During operation of the grinding machine 22, various valves shown in association with the hydraulic circuitry of FIG. 11 are activated by the electrical circuitry 154 of FIG. 12.

When the grinding machine 22 is to be utilized to shape a workpiece 22 having a left reference surface 70, an operator positions the workpiece between the head and tail stock spindles 40 and 46. A start switch 160 (line 1 of the control circuit 154) is then closed to energize a 3CR relay 162 having contacts 164 (line 2) which are closed to effect energization of a 4CR relay 166. Energization of the 4CR relay 166 closes its contacts 168 (line 4) to complete a circuit for energiz' ing the SCR relay 170. The SCR relay 170 then closes contacts 174 and 175 (line 13) to complete a circuit to energize a 3A solenoid 176.

Energization of the 3A solenoid 176 actuates a headstock control valve 180 toward the left (as viewed in FIG. 11) to port fluid under pressure to the rod end of a cylinder 182 and connects the head end of the cylinder with drain. The cylinder 182 is located in the headstock spindle drive assembly 56 (see FIG. 1). Porting fluid under pressure into the rod end of the cylinder 182 moves a piston 184 from the position shown in FIG. 11 to the position shown in FIG. 1. During this movement of the piston 184, a rack gear 186 rotates a pinion 188 (FIG. 1) which is connected to a screw 190. Rotation of the pinion 188 and screw 190 moves the headstock spindle quickly toward the right (as viewed in FIG. 1).

Upon completion of the stroke of the piston 184, a 2LS switch 190 (FIG. 11 and line 12 of FIG. 12) is opened to effect deenergization of a 9CR relay 192. It should be noted that the 9CR relay was previously held energized over its own normally open contacts 194 (line 12). The 9CR relay 192 was initially energized in a circuit including closed contacts 198 (line 11) of the 4CR relay 166.

Deenergization of the 9CR relay 192 effects actuation of a valve 202 (FIG. 11) to clamp the tailstock 26. Thus, energization of the 9CR relay opens contacts 206 and 208 (line 16 of FIG. 12) to effect energization of solenoid 209 and activation of the valve 202. This results in movement of a piston 212 in the headstock 26 under the influence of the spring 48 to press the headstock spindle 46 firmly against the workpiece 28. As the piston 212 moves toward the left (as viewed in FIG. 11) the ILS switch 214 is actuated. Actuating the lLS switch 214 completes a circuit to energize a 6CR relay 218 (FIG. 12, line 5) by a circuit which includes the now closed contacts 168 of the 4CR relay 166.

Energization of the 6CR relay 218 effects operation of the probe assembly 60 from the inactive condition of FIG. 7 to the active condition of FIG. 9. Thus upon energization of the 6CR relay, contacts 222 and 224 (line 14 of FIG. 11) are closed to energize the solenoid 134 (see FIG. 11 and line 14 of FIG. 12). As was previously explained, energization of the solenoid 134 operates the main control valve 126 to port fluid under pressure to the selector valve 138 through the conduit 130a. The selector valve 138 was previously actuated manually to the left reference surface sensing condition of FIG. 9. Therefore, energization of the solenoid 134 and operation of the main control valve 126 effects movement of the probe member 74 in a counter clockwise direction (as viewed in FIG. 9) to the active condition in which the locating surface 78 is disposed in abutting engagement with the reference surface 70 on the workpiece 28.

In addition to effecting energization of the 6CR relay 218, closing of the lLS switch 214 (line 5 of FIG. 12) completes a circuit to effect energization of a 6TR relay 228 (line 6 of FIG. 12) which is of the time delay type. After the probe assembly 60 has been moved to the active condition of FIG. 9, the 6TR relay 228 times out to close its contacts 232 (line 7 of FIG. 12). Closing the contacts 232 completes a circuit to energize a 7CR relay 236 (line 8 of FIG. 12).

Energization of the 7CR relay 236 completes a circuit to energize a solenoid 240 (line 15) which actuates a valve 242 in the hydraulic circuitry (FIG. 11) to effect slow movement of the headstock 24 toward the left (as viewed in FIG. 1). Thus, energization of the 7CR relay 236 closes contacts 244 and 246 (line 15 of FIG. 12) to energize the solenoid 240 and actuate the valve 242. It should be noted that the SCR relay (line 4 of FIG. 12) was previously energized so that normally closed contacts 248 of a 6CR relay 218 are open. If, for some reason, the normally opened contacts 248 of the 6CR relay should hang up, normally opened contacts 250CR of the relay assure that the 5CR relay 170 is deenergized to effect energization of the 7CR relay 236 and solenoid 176 prior to the energization of the solenoid 240. Therefore, the control valve 180 is in its unactuated position illustrated in FIG. 11. This enables high pressure fluid to flow to the head end of the cylinder 182.

Upon energization of the solenoid 240, the valve 242 (FIG. 11) is actuated to connect the rod end of the cylinder 182 with drain through an orifice 250 so that the piston 184 and the rack gear 186 move slowly upward (as viewed in FIGS. 1 and 11). This results in the pinion 188 and screw 190 (FIG. 1) being rotated to gradually retract the headstock spindle 40 toward the left (as viewed in FIG. 1). The spring 48 holds the tailstock spindle 46 firmly against the workpiece 28 as it is moved toward the left.

When the workpiece 28 has been moved toward the left (as viewed in FIGS. 1 and 9) through a distance sufficient to move the reference surface 70 into a predetermined position relative to grinding wheel 34, the detector switch 64 is closed by the actuator arm 82 in the manner previously explained. Actuation of the detector switch 64 (line 7 of FIG. 12) effects deenergization of the 7CR relay 236 (line 8 of FIG. 12) to deenergize the solenoid 240 (line 15 of FIG. 12). The deenergization of solenoid 240 results in the spring biased control valve 242 (FIG. 11) being actuated back to its normal position in which the piston 184 is locked in position to hold the workpiece in the predetermined location. In addition, actuation of the detector switch 64 completes the circuit to energize a 7TR relay 251 (line 9, FIG. 12) which, after a time delay, effects operation of control circuitry (not shown) to move the grinding wheel 34 into engagement with the workpiece 28. The general mode of operation of the grinding machine is similar to that described in US. Pat. No. 3,171,234 and will not be further described herein.

When operations on the workpiece have been completed, stop switch 262 is actuated (line 2 of FIG. 12) to deenergize the 4CR relay 166. Deenergization of the 4CR relay 166 results in closing of its contacts 198 (line 11 of FIG. 12) to energize the 9CR relay 192 (line 12 of FIG. 12). Energization of the 9CR relay 192 energizes the solenoid 209 (line 16 of FIG. 12) to actuate the valve 202 (FIG. 11) and release the footstock 26. In addition, deenergization of the 4CR relay 166 results in opening of its contacts 168 (line 4 of FIG. 12) to deenergize the 6CR relay 218 so that the solenoid 134 (line 14 of FIG. 12) is also deenergized. The deenergization of the solenoid 134 results in operation of the spring biased main control valve 126 to effect movement of the probe assembly 60 from the active condition to the inactive condition.

in view of the fore going description is is apparent that the workpiece locator assembly 20 can be utilized to detect when a right reference surface 52 or a left reference surface 70 is in a predetermined position in a work area. To facilitate sequential operation on workpieces 28 having different shapes, the locator assembly 20 can be utilized to locate a right reference surface 52 on one workpiece relative to the work are 30 and to subsequently locate a left reference surface 70 without disassembling the locator assembly.

The probe member 74 is connected with a double acting motor 98 by a yieldable connection 106 which enables the probe member to move relative to the motor. The yieldable connection 106 includes a pair of springs 110 and 112 of the same free lengths.

To enable the locator assembly 20 to be utilized to sequentially locate a right reference surface 52 on a first workpiece 28 relative to a work area 30 and to thereafter locate a left reference surface 70 on another workpiece relative to the work area, a selector valve 138 is associated with the motor 98. Actuation of the selector valve 138 to a first position enables the motor 98 to pivot the probe 74 in a first direction from an inactive condition to an active condition when the probe member is to be utilized to locate a right reference surface 52. Similarly, actuation of the selector valve 138 to a second position enables the motor 98 to pivot the probe member 74 in a second direction from an inactive condition to an active condition when the probe member is to be utilized to locate a left reference surface 70.

Having described one specific preferred embodiment of the invention, the following is claimed:

1. An apparatus for sequentially operating on a plurality of workpieces each of which has a reference surface facing toward either one of two opposite end portions of the workpiece, said apparatus comprising support means for moving the workpiece axially in a work area, said support means including means for supporting a first workpiece with a reference surface facing toward a first end portion of the work area and for subsequently supporting a second workpiece with a reference surface facing toward a second end portion of the work area which is opposite from said first end portion of the work area, means for moving a cutting tool into engagement with a workpiece held by said support means, control means for effecting operation of said support means to move a workpiece axially in a first direction to position the workpiece relative to the work area, sensor means for detecting when the reference surface on said first workpiece has been moved in said first direction to a predetermined position in the work area and for subsequently detecting when the reference surface on said second workpiece has been moved in said first direction to a predetermined position in the work area, said sensor means including a probe member having first surface means disposed on one side of said probe member for engaging the reference surface on said first workpiece as said first workpiece is moved axially in the first direction by said support means and second surface means disposed on another side of said probe member opposite from said one side for subsequently engaging the reference surface on said second workpiece as said second workpiece is moved axially in the first direction by said support means, said second surface means being spaced apart from said first workpiece during engagement of the reference surface on said first workpiece by said first surface means, said first surface means being spaced apart from said second workpiece during engagement of the reference surface on said second workpiece by said second surface means, and detector means for detecting when a reference surface engaged by either one of said surface means on said probe member is in a predetermined position in the work area and for effecting operation of said control means to interrupt axial movement of the workpiece by said support means in response to detection that a reference surface engaged by either one of said surface means on said probe member is in a predetermined position.

2. An apparatus set forth in claim 1 wherein said sensor means includes means for supporting said probe member for movement in opposite directions relative to the work area and means for effecting movement of said probe member in one direction relative to the work area to move said first surface means into engagement with a reference surface on said first workpiece and for effecting movement relative to the work area of said probe member in another direction opposite from said one direction to move said second surface means into engagement with a reference surface on said second workpiece.

3. An apparatus as set forth in claim 2 wherein said sensor means further includes means for effecting movement of said probe member in said other direction relative to the work area to move said first surface means away from the reference surface on said first workpiece and for effecting movement of said probe member in said one direction relative to the work area to move said second surface means away from the reference surface on said second workpiece.

4. An apparatus as set forth in claim 1 and wherein said sensor means further includes motor means operable between first and second conditions to move said probe member relative to the work area, said motor means being operable from said first condition to said second condition to move said first surface means into engagement with the reference surface on said first workpiece during operation of said apparatus on said first workpiece, said motor means being operable from said second condition to said first condition to move said second surface means into engagement with the reference surface on said second workpiece during operation of said apparatus on said second workpiece.

5. An apparatus as set forth in claim 4 wherein said motor means includes piston and cylinder having an operating stroke extending parallel to the axis of a workpiece supported by said support means.

6. An apparatus as set forth in claim 1 wherein said sensor means includes motor means for moving said probe member relative to said work area and spring means for yieldably connecting said probe member with said motor means.

7. An apparatus for operating on a workpiece having a reference surface, said apparatus comprising support means for moving a workpiece in a work area, means for moving a cutting tool into engagement with a workpiece held by said support means, means for effecting operation of said support means to move the workpiece in the work area to position the workpiece relative to the cutting tool, and sensor means for detecting when the reference surface on the workpiece is in a predetermined position in the work area, said sensor means including a probe member having a surface means for engaging the reference surface, said probe member being movable between an inactive condition in which said sensor means is ineffective to detect when a reference surface is in the predetermined position in the work area and an active condition in which said sensor means is effective to detect when a reference surface is in the predetermined position in the work area, motor means for moving said probe member between the inactive and active conditions, said motor means having an operating condition in which said motor means is effective to move said probe member and a nonoperating condition in which said motor means is ineffective to move said probe member, and connection means for yieldably interconnecting said probe member and said motor means for enabling said probe member to move relative to said motor means when said probe member is in the active condition and said motor means is in the non-operating condition.

8. An apparatus as set forth in claim 7 wherein said motor means is reversible to enable said motor means to move said probe member in opposite directions relative to the work area, said connection means including first and second springs and means for connecting said springs with said motor means to enable said motor means to move said probe member in a first direction from said inactive condition to said active condition upon operation of said motor means in one of said opposite directions and for connecting said springs with said motor means to enable said motor means to move said probe member in a second direction from said inactive condition to said active condition upon operation of said motor in the direction opposite to said one direction, and control means for effecting operation of said motor means in said one direction fo move said probe member in said first direction from said inactive condition to said active condition and for effecting operation of said motor means in said direction opposite to said one direction to move said probe member in said second direction from said inactive condition to said active condition.

9. An apparatus as set forth in claim 7 wherein said connection means includes a first spring member disposed on one side of said probe member, and a second spring member disposed on a side of said probe member opposite from said one side and in a coaxial relationship with said first spring member, and means for connecting said spring members with said motor means.

10. An apparatus as set forth in claim 7 wherein said motor means includes a cylinder, a piston disposed within said cylinder, and a piston rod connected with said piston and extending outwardly from said cyliner, said connection means including first spring element disposed adjacent to one side of said probe member in a coaxial relationship with said piston rod, a second spring element disposed adjacent to another side of said probe member in a coaxial relationship with said piston rod and said first spring element, and means for connecting said first and second spring elements with said piston rod.

11. An apparatus for sequentially operating on a plurality of workpieces each of which has a reference surface facing toward either one of two opposite end portions of the workpiece, said apparatus comprising support means for moving the workpiece axially in a work area, said support means including means for supporting a first workpiece with a reference surface facing toward a first end portion of the work area and for subsequently supporting a second workpiece with a second reference surface facing toward a second end portion of the work area which is opposite from the first end portion of the work area, means for moving a cutting tool into engagement with a workpiece held by said support means, control means for effecting operation of said support means to move a workpiece axially in a first direction to position the workpiece relative to the work area, sensor means for detecting when the reference surface on said first workpiece has been moved in said first direction to a predetermined position in the work area and for subsequently detecting when the reference surface on said second workpiece has been moved in said first direction to a predetermined position in the work area, said sensor means including a single probe member having first surface means disposed on one side of said probe member for engaging the reference surface on said first workpiece as the first workpiece is moved axially in the first direction by said support means and second surface means disposed on another side of said probe member opposite from said one side for subsequently engaging the reference surface on said second workpiece as said second workpiece is moved axially in the first direction by said support means, detector means for detecting when the reference surface engaged by either one of said surface means on said probe member is in a predetermined position in the work area and for effecting operation of said control means to interrupt axial movement of the workpiece by said support means in response to detection that the reference surface engaged by either one of said surface means on said probe member is in a predetermined position, motor means for moving said probe member in a first direction from an inactive condition to an active condition in which the reference surface on said workpiece is engageable with said first surface means and for moving said probe member in a second direction from an inactive condition in which said second surface means on said probe member is engageable with the reference on said second workpiece, and connection means for yieldably interconnecting said probe member and said motor means for enabling said probe member to move relative to said motor means when said probe member is in the active condition.

12. An apparatus for sequentially operating on a plurality of workpieces each of which has a reference surface facing toward either one of two opposite end portions of the workpiece, said apparatus comprising support means for moving the workpiece axially in a work area, said support means including means for supporting a first workpiece with a reference surface facing to ward a first end portion of the work area and for subsequently supporting a second workpiece with a second reference surface facing toward a second end portion of the work area which is opposite from the first end portion of the work area, means for moving a cutting tool into engagement with a workpiece held by said support means, control means for effecting operation of said support means to move a workpiece axially in a first direction to position the workpiece relative to the work area, sensor means for detecting when the reference surface on said first workpiece has been moved in said first direction to a predetermined position in the work area and for subsequently detecting when the reference surface on said second workpiece has been moved in said first direction to a predetermined posi tion in the work area, said sensor means including a probe member having first surface means disposed on one side of said probe member for engaging the reference surface on said first workpiece as the first workpiece is moved axially in the first direction by said support means and second surface means disposed on another side of said probe member opposite from said one side for subsequently engaging the reference surface on said second workpiece as said second workpiece is moved axially in the first direction by said support means, detector means for detecting when the reference surface engaged by either one of said surface means on said probe member is in a predetermined position in the work area and for effecting operation of said control means to interrupt axial movement of the workpiece by said support means in response to detection that the reference surface engaged by either one of said surface means on said probe member is in a pre determined position, motor means for moving said probe member in a first direction from an inactive condition to an active condition in which the reference sur' face on said workpiece is engageable with said first surface means and for moving said probe member is a second direction from an inactivecondition in which said second surface means on said probe member is engageable with the reference on said second workpiece, and connection means for yieldably interconnecting said probe member and said motor means for enabling said probe member to move relative to said motor means when said probe member is in the active condition, said connection means includes first and second spring members disposed adjacent to opposite sides of said probe member.

13. An apparatus as set forth in claim 7 wherein said connection means includes spring means for enabling relative movement to occur between said motor means and probe member when said probe member is in the active condition and said motor means is in the nonoperating condition, said spring means being compressible under the influence of forces applied to said probe member by the workpiece when said probe member is in the active condition and the workpiece is being moved by said support means.

14. An apparatus as set forth in claim 7 wherein said connection means includes spring means for moving said probe member relative to said motor means when said probe member is in the active condition and the workpiece is being moved by said support means with said motor means in the nonoperating condition.

15. An apparatus for sequentially operating on a plurality of workpieces each of which has a reference surface facing toward either one of two opposite end portions of the workpiece, said apparatus comprising support means for moving the workpiece axially in a work area, said support means including means for supporting a first workpiece with a reference surface facing to ward a first end portion of the work area and for subsequently supporting a second workpiece with a reference surface facing toward a second end portion of the work area which is opposite from said first end portion of the work area, means for moving a cutting tool into engagement with a workpiece held by said support means, control means for effecting operation of said support means to move a workpiece axially in a first direction to position the workpiece relative to the work area, sensor means for detecting when the reference surface on said first workpiece has been moved in said first direction to a predetermined position in the work area and for subsequently detecting when the reference surface on said second workpiece has been moved in said first direction to a predetermined position in the work area, said sensor means including a single probe member having first surface means disposed on one side of said probe member for engaging the reference surface on said first workpiece as said first workpiece is moved axially in the first direction by said support means and second surface means disposed on another side of said probe member opposite from said one side for subsequently engaging the reference surface on said second workpiece as said second workpiece is moved axially in the first direction by said support means, said second surface means being spaced apart from said first workpiece during engagement of the reference surface on said first workpiece by said first surface means, said first surface means being spaced apart from said second workpiece during engagement of the reference surface on said second workpiece by said second surface means, motor means for moving said probe member in one direction to move said first surface means into engagement with the reference surface on the first workpiece and for moving said probe member in another direction opposite from said one direction to move said second surface means into engagement with the reference surface on the second workpiece, connection means for yieldably interconnecting said probe member and said motor means for enabling said probe member to move relative to said motor means when said motor means is in a nonoperating condition and said first surface means is disposed in engagement with the reference surface on the first workpiece and for enabling said probe member to move relative to said motor means when said motor means is in the nonoperating condition and said second surface means is disposed in engagement with the reference surface on the second workpiece, and detector means for detecting when a reference surface engaged by either one of said surface means on said probe member is in a predetermined position in the work area and for effecting operation of said control means to interrupt axial movement of the workpiece by said support means in response to detection that a reference surface engaged by either one of said surface means on said probe member is in a predetermined position.

16. An apparatus as set forth in claim 15 wherein said connection means includes first spring means for enabling said probe member to move in said other direction upon movement of the first workpiece in said first direction when said motor means is in the nonoperating condition and said first surface means is disposed in engagement with the reference surface on the first workpiece, and second spring means for enabling said probe member to move in said other direction upon movement of the second workpiece in said first direction when said motor means is in the nonoperating condition and said second surface means is disposed in engagement with the reference surface on the second workpiece.

17. An apparatus as set forth in claim 16 wherein said first spring means is compressible under the influence of forces applied to said probe member by the first 0nd workpiece, said second spring means being effective to move said said probe member in said other direction upon movement of the second workpiece in said first direction with said motor means in the nonoperating condition and said second surface means disposed in engagement with the reference surface on the second workpiece. 

1. An apparatus for sequentially operating on a plurality of workpieces each of which has a reference surface facing toward either one of two opposite end portions of the workpiece, said apparatus comprising support means for moving the workpiece axially in a work area, said support means including means for supporting a first workpiece with a reference surface facing toward a first end portion of the work area and for subsequently supporting a second workpiece with a reference surface facing toward a second end portion of the work area which is opposite from said first end portion of the work area, means for moving a cutting tool into engagement with a workpiece held by said support means, control means for effecting operation of said support means to move a workpiece axially in a first direction to position the workpiece relative to the work area, sensor means for detecting when the reference surface on said first workpiece has been moved in said first direction to a predetermined position in the work area and for subsequently detecting when the reference surface on said second workpiece has been moved in said first direction to a predetermined position in the work area, said sensor means including a probe member having first surface means disposed on one side of said probe member for engaging the reference surface on said first workpiece as said first workpiece is moved axially in the first direction by said support means and second surface means disposed on another side of said probe member opposite from said one side for subsequently engaging the reference surface on said second workpiece as said second workpiece is moved axially in the first direction by said support means, said second surface means being spaced apart from said first workpiece during engagement of the reference surface on said first workpiece by said first surface means, said first surface means being spaced apart from said second workpiece during engaGement of the reference surface on said second workpiece by said second surface means, and detector means for detecting when a reference surface engaged by either one of said surface means on said probe member is in a predetermined position in the work area and for effecting operation of said control means to interrupt axial movement of the workpiece by said support means in response to detection that a reference surface engaged by either one of said surface means on said probe member is in a predetermined position.
 1. An apparatus for sequentially operating on a plurality of workpieces each of which has a reference surface facing toward either one of two opposite end portions of the workpiece, said apparatus comprising support means for moving the workpiece axially in a work area, said support means including means for supporting a first workpiece with a reference surface facing toward a first end portion of the work area and for subsequently supporting a second workpiece with a reference surface facing toward a second end portion of the work area which is opposite from said first end portion of the work area, means for moving a cutting tool into engagement with a workpiece held by said support means, control means for effecting operation of said support means to move a workpiece axially in a first direction to position the workpiece relative to the work area, sensor means for detecting when the reference surface on said first workpiece has been moved in said first direction to a predetermined position in the work area and for subsequently detecting when the reference surface on said second workpiece has been moved in said first direction to a predetermined position in the work area, said sensor means including a probe member having first surface means disposed on one side of said probe member for engaging the reference surface on said first workpiece as said first workpiece is moved axially in the first direction by said support means and second surface means disposed on another side of said probe member opposite from said one side for subsequently engaging the reference surface on said second workpiece as said second workpiece is moved axially in the first direction by said support means, said second surface means being spaced apart from said first workpiece during engagement of the reference surface on said first workpiece by said first surface means, said first surface means being spaced apart from said second workpiece during engaGement of the reference surface on said second workpiece by said second surface means, and detector means for detecting when a reference surface engaged by either one of said surface means on said probe member is in a predetermined position in the work area and for effecting operation of said control means to interrupt axial movement of the workpiece by said support means in response to detection that a reference surface engaged by either one of said surface means on said probe member is in a predetermined position.
 2. An apparatus set forth in claim 1 wherein said sensor means includes means for supporting said probe member for movement in opposite directions relative to the work area and means for effecting movement of said probe member in one direction relative to the work area to move said first surface means into engagement with a reference surface on said first workpiece and for effecting movement relative to the work area of said probe member in another direction opposite from said one direction to move said second surface means into engagement with a reference surface on said second workpiece.
 3. An apparatus as set forth in claim 2 wherein said sensor means further includes means for effecting movement of said probe member in said other direction relative to the work area to move said first surface means away from the reference surface on said first workpiece and for effecting movement of said probe member in said one direction relative to the work area to move said second surface means away from the reference surface on said second workpiece.
 4. An apparatus as set forth in claim 1 and wherein said sensor means further includes motor means operable between first and second conditions to move said probe member relative to the work area, said motor means being operable from said first condition to said second condition to move said first surface means into engagement with the reference surface on said first workpiece during operation of said apparatus on said first workpiece, said motor means being operable from said second condition to said first condition to move said second surface means into engagement with the reference surface on said second workpiece during operation of said apparatus on said second workpiece.
 5. An apparatus as set forth in claim 4 wherein said motor means includes piston and cylinder having an operating stroke extending parallel to the axis of a workpiece supported by said support means.
 6. An apparatus as set forth in claim 1 wherein said sensor means includes motor means for moving said probe member relative to said work area and spring means for yieldably connecting said probe member with said motor means.
 7. An apparatus for operating on a workpiece having a reference surface, said apparatus comprising support means for moving a workpiece in a work area, means for moving a cutting tool into engagement with a workpiece held by said support means, means for effecting operation of said support means to move the workpiece in the work area to position the workpiece relative to the cutting tool, and sensor means for detecting when the reference surface on the workpiece is in a predetermined position in the work area, said sensor means including a probe member having a surface means for engaging the reference surface, said probe member being movable between an inactive condition in which said sensor means is ineffective to detect when a reference surface is in the predetermined position in the work area and an active condition in which said sensor means is effective to detect when a reference surface is in the predetermined position in the work area, motor means for moving said probe member between the inactive and active conditions, said motor means having an operating condition in which said motor means is effective to move said probe member and a nonoperating condition in which said motor means is ineffective to move said probe member, and connection means for yieldably interconnecting said probe member and said motor means for enabling said probe member to move relative to said motor means when said probe member is in the active condition and said motor means is in the non-operating condition.
 9. An apparatus as set forth in claim 7 wherein said connection means includes a first spring member disposed on one side of said probe member, and a second spring member disposed on a side of said probe member opposite from said one side and in a coaxial relationship with said first spring member, and means for connecting said spring members with said motor means.
 10. An apparatus as set forth in claim 7 wherein said motor means includes a cylinder, a piston disposed within said cylinder, and a piston rod connected with said piston and extending outwardly from said cyliner, said connection means including first spring element disposed adjacent to one side of said probe member in a coaxial relationship with said piston rod, a second spring element disposed adjacent to another side of said probe member in a coaxial relationship with said piston rod and said first spring element, and means for connecting said first and second spring elements with said piston rod.
 11. An apparatus for sequentially operating on a plurality of workpieces each of which has a reference surface facing toward either one of two opposite end portions of the workpiece, said apparatus comprising support means for moving the workpiece axially in a work area, said support means including means for supporting a first workpiece with a reference surface facing toward a first end portion of the work area and for subsequently supporting a second workpiece with a second reference surface facing toward a second end portion of the work area which is opposite from the first end portion of the work area, means for moving a cutting tool into engagement with a workpiece held by said support means, control means for effecting operation of said support means to move a workpiece axially in a first direction to position the workpiece relative to the work area, sensor means for detecting when the reference surface on said first workpiece has been moved in said first direction to a predetermined position in the work area and for subsequently detecting when the reference surface on said second workpiece has been moved in said first direction to a predetermined position in the work area, said sensor means including a single probe member having first surface means disposed on one side of said probe member for engaging the reference surface on said first workpiece as the first workpiece is moved axially in the first direction by said support means and second surface means disposed on another side of said probe member opposite from said one side for subsequently engaging the reference surface on said second workpiece as said second workpiece is moved axially in the first direction by said support means, detector means for detecting when the reference surface engaged by either one of said surface means on said probe member is in a predetermined position in the work area and for effecting operation of said control means to interrupt axial movement of the workpiece by said support means in response to detection that the reference surface engaged by either one of said surface means on said probe member is in a predetermined position, motor means for moving said probe member in a first direction from an inactive condition to an active condition in which the reference surface on said workpiece is engageable with said first surface means and for moving said probe member in a second direction from an inactive condition in which said second surface means on said probe member is engageable with the reference on said second workpiece, and connection means for yieldably interconnecting said probe member and said motor means for enabling said probe member to move relative to said motor means when said probe member is in the active condition.
 12. An apparatus for sequentially operating on a plurality of workpieces each of which has a reference surface facing toward either one of two opposite end portions of the workpiece, said apparatus comprising support means for moving the workpiece axially in a work area, said support means including means for supporting a first workpiece with a reference surface facing toward a first end portion of the work area and for subsequently supporting a second workpiece with a second reference surface facing toward a second end portion of the work area which is opposite from the first end portion of the work area, means for moving a cutting tool into engagement with a workpiece held by said support means, control means for effecting operation of said support means to move a workpiece axially in a first direction to position the workpiece relative to the work area, sensor means for detecting when the reference surface on said first workpiece has been moved in said first direction to a predetermined position in the work area and for subsequently detecting when the reference surface on said second workpiece has been moved in said first direction to a predetermined position in the work area, said sensor means including a probe member having first surface means disposed on one side of said probe member for engaging the reference surface on said first workpiece as the first workpiece is moved axially in the first direction by said support means and second surface means disposed on another side of said probe member opposite from said one side for subsequently engaging the reference surface on said second workpiece as said second workpiece is moved axially in the first direction by said support means, detector means for detecting when the reference surface engaged by either one of said surface means on said probe member is in a predetermined position in the work area and for effecting operation of said control means to interrupt axial movement of the workpiece by said support means in response to detection that the reference surface engaged by either one of said surface means on said probe member is in a predetermined position, motor means for moving said probe member in a first direction from an inactive condition to an active condition in which the reference surface on said workpiece is engageable with said first surface means and for moving said probe member is a second direction from an inactivecondition in which said second surface means on said probe member is engageable with the reference on said second workpiece, and connection means for yieldably interconnecting said probe member and said motor means for enabling said probe member to move relative to said motor means when said probe member is in the active condition, said connection means includes first and second spring members disposed adjacent to opposite sides of said probe member.
 13. An apparatus as set forth in claim 7 wherein said connection means includes spring means for enabling relative movement to occur between said motor means and probe member when said probe member is in the active condition and said motor means is in the nonoperating condition, said spring means being compressible under the influence of forces applied to said probe member by the workpiece when said probe member is in the active condition and the workpiece is being moved by said support means.
 14. An apparatus as set forth in claim 7 wherein said connection means includes spring means for moving said probe member relative to said motor means when said probe member is in the active condition and the workpiece is being moved by said support means with said motor means in the nonoperating condition.
 15. An apparatus for sequentially operating on a plurality of workpieces each of which has a reference surface facing toward either one of two opposite end portions of the workpiece, said apparatus comprising support means for moving the workpiece axially in a work area, said support means including means for supporting a first workpiece with a reference surface facing toward a first end portion of the work area and for subsequently supporting a second workpiece with a reference surface facing toward a second end portion of the work area which is opposite from said first end portion of the work area, means for moving a cutting tool into engagement with a workpiece held by said support means, control means for effecting operation of said support means to move a workpiece axially in a first direction to position the workpiece relative to the work area, sensor means for detecting when the reference surface on said first workpiece has been moved in said first direction to a predetermined position in the work area and for subsequently detecting when the reference surface on said second workpiece has been moved in said first direction to a predetermined position in the work area, said sensor means including a single probe member having first surface means disposed on one side of said probe member for engaging the reference surface on said first workpiece as said first workpiece is moved axially in the first direction by said support means and second surface means disposed on another side of said probe member opposite from said one side for subsequently engaging the reference surface on said second workpiece as said second workpiece is moved axially in the first direction by said support means, said second surface means being spaced apart from said first workpiece during engagement of the reference surface on said first workpiece by said first surface means, said first surface means being spaced apart from said second workpiece during engagement of the reference surface on said second workpiece by said second surface means, motor means for moving said probe member in one direction to move said first surface means into engagement with the reference surface on the first workpiece and for moving said probe member in another direction opposite from said one direction to move said second surface means into engagement with the reference surface on the second workpiece, connection means for yieldably interconnecting said probe member and said motor means for enabling said probe member to move relative to said motor means when said motor means is in a nonoperating condition and said first surface means is disposed in engagement with the reference surface on the first workpiece and for enabling said probe member to move relative to said motor means when said motor means is in the nonoperating condition and said second surface means is disposed in engagement with the reference surface on the second workpiece, and detector means for detecting when a reference surface engaged by either one of said surface means on said probe member is in a predetermined position in the work area and for effecting operation of said control means to interrupt axial movement of the workpiece by said support means in response to detection that a reference surface engaged by either one of said surface means on said probe member is in a predeterMined position.
 16. An apparatus as set forth in claim 15 wherein said connection means includes first spring means for enabling said probe member to move in said other direction upon movement of the first workpiece in said first direction when said motor means is in the nonoperating condition and said first surface means is disposed in engagement with the reference surface on the first workpiece, and second spring means for enabling said probe member to move in said other direction upon movement of the second workpiece in said first direction when said motor means is in the nonoperating condition and said second surface means is disposed in engagement with the reference surface on the second workpiece.
 17. An apparatus as set forth in claim 16 wherein said first spring means is compressible under the influence of forces applied to said probe member by the first workpiece during movement of the first workpiece in the first direction when said motor means is in the nonoperating condition and said first surface means is in engagement with the reference surface on the first workpiece.
 18. An apparatus as set forth in claim 17 wherein said second spring means is compressible upon operation of said motor means to move said second surface means into engagement with the reference surface on the second workpiece, said second spring means being effective to move said said probe member in said other direction upon movement of the second workpiece in said first direction with said motor means in the nonoperating condition and said second surface means disposed in engagement with the reference surface on the second workpiece. 